Math course to prove/polish quant skills?

Folks,

I re-wrote the GMAT in July after 6 months of exhaustive studying (focusing about 80-85% of my time on quant) and was happy to walk away with a 670 (Q44,V38). My goal was 700+, but even after taking two months off I feel completely burnt out from studying when I pick up a book to study from. A 670 should bode well for me, as its rougly 40-70 pts above my target schools averages (some tier 2 and a few fringe tier 1 Canadian Bschools) and should help overshadow a usable, but not an overly impressive, GPA and WE.

It was suggested to me that I take a math course at a local college to shore up my quant skills and to demonstrate my strength in this area to adcoms. On the GMAT, nearly all of my quant errors were from silly or careless errors not from a problem understanding the underlying fundamentals or concepts (VERY frustrating). Anyways, I had a look at the courses... which one(s) should I take as it relates to the math needed to complete an MBA?

-Intergral Calculus
-Differential Calculus
-"Business" Mathematics (Begin with the mathematics of merchandising, a review of simple interest, followed by compound interest and applications.)
-Business Statistics, Advanced (Topics include: probability, decision analysis, sampling distributions, applications of sampling and risk analysis, statistical estimation and hypothesis testing, regression and correlation, analysis of variance, time series, index numbers, Bayes' rule, and an introduction to linear programming.)
-Finance and Accounting Math (Gain an introduction to the concepts and procedures of the time value of money calculations used in Mathematics of Finance. Topics include simple interest, compound interest, simple and general annuities, bonds and cost-benefit analysis)

I'm thinking for sure the stats course would be helpful, but is there any need to redo calculus again? I was good at it 7 years ago but barely remember it now.

Also, all of these course last about 14 weeks. By the time I've got my "A" it'll be December/January. I plan on applying for Round 1 at all my target schools which is mid-October. Will successfully completing these courses have any impact on their admission decision? By the time they get my "A" I figure they'll probably made up their minds on whether to admit me or not.

Thoughts?